1. Field of the Invention
This invention relates to an assembly for introducing and stabilizing a trocar or other medical instrument preferably, but not exclusively, during an open laparoscopic surgical procedure and includes a base having a sealing surface formed on the exterior thereof. The sealing surface comprises a predetermined cross-sectional configuration which is shaped to dilate and/or substantially conform to the resulting shape of an incision type entry site and thereby facilitate sealing engagement between the sealing surface of the base and the anatomical tissue contiguous to the entry site.
2. Description of the Related Art
For many years, laparoscopic surgery has been used on patients, when applicable, in order to avoid the serious and significant disadvantages generally associated with open surgery. Open surgery, as is generally recognized, requires that large incisions be made on a patient's body in order to more completely open a body cavity and allow the surgeon clear access to the organs or anatomical tissue involved. In contrast, laparoscopic surgical techniques involve the use of small diameter, long handled instruments including forceps, scissors, retractors, dissectors, etc. which are specifically designed and structured to be inserted through a small “entry site” formed in the wall of the body cavity being entered. Further, in order to more clearly observe the interior of the body cavity and the anatomical tissue or organs involved in the surgical procedure, an endoscopic camera or endoscope passes through the entry site to allow the medical personnel to view the interior portions on a monitor or other display facility. There are obvious advantages of endoscopic or laparoscopic surgery over the aforementioned open surgery technique based upon the minimally invasive procedures utilized on the patient.
Once the entry site has been prepared and access to the intended body cavity has been obtained, a trocar, cannula or like device is positioned into the entry site in order that the aforementioned types of laparoscopic instruments may be readily positioned into the interior of the body cavity and in operative contact with the organ or bodily tissue involve in the surgical procedure. Prior to conducting the intended surgical procedures involved, the body cavity is expanded so as to enlarge the working space for the surgeon, by insufflation. Insufflation is a process of injecting gas into the body cavity in order to create an expanded chamber at least partially filled with gas. In order to maintain the expanded area of the body cavity and facilitate the surgical procedure, the trocar assembly, cannula or an introducer device must be designed and structured to reduce the leakage of the insufflating gas from the entry site.
The more commonly used laparoscopic surgical techniques typically involve creating an entry site utilizing a sharpened point or bladed obturator which essentially “punctures” the anatomical tissue defining the surrounding wall of the body cavity being entered. In doing so, it is not uncommon to cause damage to interior organs or other anatomical tissue including blood vessels or the like. In certain instances, such damage can be significant, e.g., can lead to infection, and may result in severe trauma or death to the patient. The formation of the entry site in this manner is generally referred to as a “closed” laparoscopic technique.
However, in 1971 a doctor named Harrith Hasson of Chicago, Illinois developed a method of forming the entry site for the body cavity which is now referred to as the “open laparoscopic” technique. The purpose of the Hasson method is to eliminate or significantly reduce severe damage to the patient caused by the forced entry or puncture of an obturator or like entry instrument through the wall of the body cavity. In the Hasson technique, various medical instruments including a scalpel, scissors, retractors, etc. are used to carefully dissect each layer of the anatomical tissue associated with the cavity wall, thereby forming the entry site in a precise, controlled and safe manner. Once the entry site is so formed, a blunt headed trocar is inserted therethrough and the insufflation of the body cavity takes place.
While not initially accepted in the medical profession, in 1997 the Hasson method or technique was compared with the more commonly used, “closed” laparoscopic technique. Specifically, 489,000 closed laparoscopic and 12,400 open laparoscopic procedures were compared in a study conducted in the Netherlands. The Hasson method was shown to reduce laparoscopic access related injuries significantly. More specifically, injuries to organs was reduced by almost 50% and no patient suffered a single blood vessel injury. The study, therefore, concluded that the open laparoscopic method of access or entry site formation be advocated when minimally invasive surgical techniques are applicable, because it is safer than the more commonly used closed method.
However, and as set forth above, utilization of the Hasson method involves the formation of an “incision type” of entry site. Accordingly, the entry site so formed has an at least partially elongated shape or configuration, like a “slit.” As such, the insertion of a commonly structured introducer device into the entry site may result in a greater tendency of leakage of the insufflating gas. More specifically, conventionally structured introducer instruments or devices are typically configured to be entirely round or circular and are thought by the inventor herein to be more susceptible to gas leaks about the exterior surface thereof. As a result it is difficult, if not impossible, to maintain the insufflated state of the abdomen, i.e., the preferred, expanded work area within the body cavity.
Accordingly, because of the increased acceptance of the Hasson method of open laparoscopic surgery there is a need for an improved introducer assembly. Any such introducer assembly developed would preferably be designed and structured to restrict the leakage of insufflating gas from the body cavity during the introduction of medical instruments, as well as during the entire surgical procedure. Any such improved introducer assembly developed should also be capable of being securely anchored and maintained in its intended position at and/or within the entry site and further, include structure specifically designed to define or create a fluid type seal between exterior portions of the improved introducer assembly and the anatomical tissue contiguous to the entry site, particularly of the type formed by the Hasson method. Any such improved introducer assembly should be structured to be used specifically, but not exclusively, with an open laparoscopic technique. In doing so, the disadvantages of true open surgery as well as problems associated with laparoscopic access related injuries would be significantly reduced.